1. Field of the Invention
The present invention relates to an image forming apparatus.
2. Description of the Related Art
An image forming apparatus includes various components (load), and electric power needs to be supplied to that loads. Examples of the load include a sheet transporting system, a motor for driving a photosensitive member and the like, various chargers, a heater of a fixing device, and a control board. It is desirable to reduce such electric power used in energy-saving mode of the image forming apparatus, preferably reducing the amount of the electric power to zero.
For reducing the electric power to zero at the time of energy-saving mode, it is necessary to supply electric power by a battery of an image forming apparatus. However, extra energy is required for charging the battery, and if such energy is obtained from an alternating current supply, the total energy of the image forming apparatus is not sufficiently saved. Thus, charging the battery using a unit other than a power supply (commercial power supply) generally preinstalled in the image forming apparatus is necessary. An image forming apparatus using a photo-electric cell (solar battery) as the unit other than the commercial power supply is widely known. However, the image forming apparatus is usually installed inside a room and chances of receiving sunlight are less. Thus, by using the solar battery, it is difficult to effectively save energy.
Furthermore, a lamp-light of a scanner is also used in a conventional technology. Specifically, when scanning an original document, utilization of an amount of the lamp-light is very less; and therefore, a major amount of a light illuminating the original document is not used. Thus, by storing such unused energy in the battery, the total energy of the image forming apparatus can be saved.
The conventional technologies for such image forming apparatus are disclosed in Japanese Patent Application Laid-open No. H3-87760 and Japanese Patent Application Laid-open No. 2004-88649. In the former technology, the photo-electric cell is arranged in the image forming apparatus that forms an image by illuminating an original document using an illuminating lamp. Specifically, the photo-electric cell is mounted on a position where the light of the illuminating lamp is received, and electric power is supplied from the photo-electric cell to at least one component of the image forming apparatus. In the latter technology, the image forming apparatus having an original-document reading unit includes an energy converting unit and an electrical storage unit for generating and storing electric power. Specifically, the image reading unit reads the image on the original document by illuminating the original document using a scanner lamp. The energy converting unit converts, upon receiving the light from the scanner lamp, light energy into electric power. The electrical storage unit stores therein electric power converted by the energy converting unit. Thus, by disposing the photo-electric cell at a base plate portion of the scanner, and by using the lamp-light of the scanner, electric power can be generated. By charging that electric power to the electrical storage unit, electric power can be used in the energy-saving mode.
In the conventional technologies mentioned above, the photo-electric cell is fixed to a base plate portion of the scanner. Therefore, the amount of light fluctuates depending on a scanning position at the time of the scanner operations. Thus, the energy cannot be effectively stored. For controlling fluctuations of the amount of light to effectively store the energy, an area of the photo-electric cell needs to be widened. Consequently, a necessary cost increases.